Help! By "caucasian" do they mean 'from the mountains of that name' or do they mean it in the American sense of 'white men'?

http://en.wikipedia.org/wiki/Cau.../ Caucasian_race

"The Caucasian race, sometimes the Caucasoid race,[1][2] is defined by the Oxford English Dictionary as "relating to a broad division of humankind covering peoples from Europe, the Middle East, Central Asia, and parts of South Asia" or "white-skinned; of European origin" or "relating to the region of the Caucasus in SE Europe".[3]"


^^I'm guessing that one.

Is there any informed speculation as to what fitness cost is associated with lactase persistence? The advantage is obvious, and the drawbacks can't be all that serious given that lactose tolerance has been driven near to fixation in northern Europe - but there must be some reason that the switch normally got flipped to 'off' in the baseline human population...

but there must be some reason that the switch normally got flipped to 'off' in the baseline human population...

it is flipped off in all mammals in adults. i am told that east asians show some evidence of selection against LP alleles. almost trivially there has to be some metabolic cost. but in any case, the LD block is enormous around LCT, wouldn't such homogenizing tweak other aspects of genetic variation.